c# 7 Initial Commit

Author: SteveGoodman

.gitignore

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+## Ignore Visual Studio temporary files, build results, and
+## files generated by popular Visual Studio add-ons.
+
+# User-specific files
+*.suo
+*.user
+*.sln.docstates
+
+# Build results
+[Dd]ebug/
+[Dd]ebugPublic/
+[Rr]elease/
+x64/
+build/
+bld/
+[Bb]in/
+[Oo]bj/
+
+# MSTest test Results
+[Tt]est[Rr]esult*/
+[Bb]uild[Ll]og.*
+
+#ignore thumbnails created by windows
+Thumbs.db
+#Ignore files build by Visual Studio
+*.obj
+*.exe
+*.pdb
+*.user
+*.aps
+*.pch
+*.vspscc
+*_i.c
+*_p.c
+*.ncb
+*.suo
+*.tlb
+*.tlh
+*.bak
+
+*.cache
+
+*.ilk
+
+*.log
+
+*.orig
+
+# Windows image file caches
+Thumbs.db
+ehthumbs.db
+
+# Visual Studio profiler
+*.psess
+*.vsp
+*.vspx
+
+# ReSharper is a .NET coding add-in
+_ReSharper*/
+*.[Rr]e[Ss]harper
+*.DotSettings.user
+[Tt]est[Rr]esult*
+
+# NuGet Packages Directory
+packages/
+## TODO: If the tool you use requires repositories.config uncomment the next line
+#!packages/repositories.config
+
+# Enable "build/" folder in the NuGet Packages folder since NuGet packages use it for MSBuild targets
+# This line needs to be after the ignore of the build folder (and the packages folder if the line above has been uncommented)
+!packages/build/
+
+# Windows Store app package directory
+AppPackages/
+
+
+
+# Microsoft Fakes
+FakesAssemblies/
+
+# Backup & report files from converting an old project file to a newer
+# Visual Studio version. Backup files are not needed, because we have git ;-)
+_UpgradeReport_Files/
+Backup*/
+UpgradeLog*.XML
+UpgradeLog*.htm
+/.gitconfig

CSharp7Console.sln

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+
+Microsoft Visual Studio Solution File, Format Version 12.00
+# Visual Studio 15
+VisualStudioVersion = 15.0.26206.0
+MinimumVisualStudioVersion = 10.0.40219.1
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "CSharp7Console", "CSharp7Console\CSharp7Console.csproj", "{FC109014-DEDF-4C6B-886A-4651D6EF3539}"
+EndProject
+Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Solution Items", "Solution Items", "{557D7F3D-0561-492A-B5BC-C4622144F450}"
+	ProjectSection(SolutionItems) = preProject
+		readme.md = readme.md
+	EndProjectSection
+EndProject
+Global
+	GlobalSection(SolutionConfigurationPlatforms) = preSolution
+		Debug|Any CPU = Debug|Any CPU
+		Release|Any CPU = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(ProjectConfigurationPlatforms) = postSolution
+		{FC109014-DEDF-4C6B-886A-4651D6EF3539}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{FC109014-DEDF-4C6B-886A-4651D6EF3539}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{FC109014-DEDF-4C6B-886A-4651D6EF3539}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{FC109014-DEDF-4C6B-886A-4651D6EF3539}.Release|Any CPU.Build.0 = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(SolutionProperties) = preSolution
+		HideSolutionNode = FALSE
+	EndGlobalSection
+EndGlobal

CSharp7Console/01Tuples.cs

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+using System;
+
+namespace CSharp7Console
+{
+    public class Tuples
+    {
+
+        //Currently tuples are ref types, and immutable, meaning each time you change a value a new object is created
+        //this makes them very inefficient, but thread safe.
+        //New  Tuples are value types,  making them still thread safe, but now more efficient.
+
+        private static Tuple<int, string> GetEmployeeByIdExisting(int employeeId)
+        {
+            var empAge = 32;
+            var dept = "HR";
+            return new Tuple<int, string>(empAge, dept);
+        }
+
+        //Shortened syntax for the tuple
+        private static (int, string) GetEmployeeByIdShortenedSyntax(int employeeId)
+        {
+            var empAge = 32;
+            var dept = "HR";
+            return (empAge, dept);
+        }
+
+        //Shortened named fields in the tuple
+        private static (int age, string department) GetEmployeeByIdNamedFields(int employeeId)
+        {
+            var empAge = 32;
+            var dept = "HR";
+            return (empAge, dept);
+        }
+
+        public static void TupleExample()
+        {
+            var employeeTuple = GetEmployeeByIdExisting(1);
+            var age = employeeTuple.Item1;
+            var dept = employeeTuple.Item2;
+
+            //newer approach with shortened syntax..
+            var employeeShortSyntaxTuple = GetEmployeeByIdShortenedSyntax(1);
+            age = employeeShortSyntaxTuple.Item1;
+            dept = employeeShortSyntaxTuple.Item2;
+
+            //newer approach with named fields..
+            var employee = GetEmployeeByIdNamedFields(1);
+            age = employee.age;
+            dept = employee.department;   //bug reverts to items2
+            dept = employee.Item2;        //intelli sense is  screwed up..
+
+            Console.WriteLine($"{age} {dept}");
+        }
+
+    }
+}

CSharp7Console/02Deconstruction.cs

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+using System;
+
+namespace CSharp7Console
+{
+    public class Deconstruction
+    {
+        //Shortened named fields in the tuple
+        private static (int age, string department) GetEmployeeByIdNamedFields(int employeeId)
+        {
+            var empAge = 32;
+            var dept = "HR";
+            return (empAge, dept);
+        }
+
+        public static void DeconstructionExample()
+        {
+            //deconstruct immediately and remove the need to hold onto the tuple.
+            (int age, string dept) = GetEmployeeByIdNamedFields(1);
+            Console.WriteLine($"{age} {dept}");
+
+            //or with var
+            (var employeeAge, var employeeDept) = GetEmployeeByIdNamedFields(1);
+            Console.WriteLine($"{employeeAge} {employeeDept}");
+
+
+            //Even lazier var...
+            var (employeeAge2, employeeDept2) = GetEmployeeByIdNamedFields(1);
+            Console.WriteLine($"{employeeAge2} {employeeDept2}");
+        }
+
+    }
+}

CSharp7Console/03LocalFunctions.cs

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+using System;
+
+namespace CSharp7Console
+{
+    public class LocalFunctions
+    {
+        /// <summary>
+        /// Embed a function within a function, this gives the advantage that no other method can call the embedded function.
+        /// You can't test the embedded
+        /// </summary>
+        /// <returns></returns>
+        private static int GetSalary()
+        {
+            var salary = GetBonus() * 2;
+
+            return salary;
+
+            int GetBonus()
+            {
+                return 10000;
+            }
+        }
+
+        public static void LocalFunctionExample()
+        {
+            Console.WriteLine("Salary is: " + GetSalary());
+        }
+    }
+}

CSharp7Console/04OutParams.cs

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+using System;
+
+namespace CSharp7Console
+{
+    public class OutParams
+    {
+        public static void GetDetails(out int userId, out string username)
+        {
+            userId = 12;
+            username = "Test User";
+        }
+
+        private  static void OutParamsExample()
+        {
+            //As it currently stands
+            int userId;
+            string userName;
+            GetDetails(out userId, out userName);
+
+            //new method
+            GetDetails(out int userIdNew, out string userNameNew);
+            Console.WriteLine($"{userIdNew} {userNameNew}");
+
+            //Use var instead of actual  type..
+            GetDetails(out var userIdVar, out var userNameVar);
+
+            //Talk of allowing *, but not implemented.
+            //GetDetails(out var userIdVar, *);
+
+        }
+
+    }
+}

CSharp7Console/05PatternMatching.cs

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+
+using System;
+
+namespace CSharp7Console
+{
+    public class PatternMatching
+    {
+        private enum ShapeType
+        {
+            Circle,
+            Rectange
+        }
+
+        private class Shape { }
+        private class Circle : Shape { public int Radius => 100; }
+        private class Rectangle : Shape
+        {
+            public int Length => 100;
+            public int Height => 120;
+        }
+
+        private static Shape GetShapeFactory(ShapeType style)
+        {
+            switch (style)
+            {
+                case ShapeType.Circle:
+                    return new Circle();
+                case ShapeType.Rectange:
+                    return new Rectangle();
+                default:
+                    return null;
+            }
+        }
+
+        public static void SwitchPatternMatchingExample()
+        {
+            var shape = GetShapeFactory(ShapeType.Rectange);
+
+            switch (shape)
+            {
+                case Circle c:
+                    Console.WriteLine($"circle with radius {c.Radius}");
+                    break;
+                case Rectangle s when (s.Length == s.Height):
+                    Console.WriteLine($"{s.Length} x {s.Height} square");
+                    break;
+                case Rectangle r:
+                    Console.WriteLine($"{r.Length} x {r.Height} rectangle");
+                    break;
+                default:
+                    Console.WriteLine("<unknown shape>");
+                    break;
+                case null:
+                    throw new ArgumentNullException(nameof(shape));
+            }
+        }
+
+        private static object GetMultipler()
+        {
+            return 100;
+        }
+
+        public static void PatternMatchingExample()
+        {
+            var o = GetMultipler();
+
+            if (o is null) return;
+
+            if (o is int i || o is string s && int.TryParse(s, out i))
+            {
+                //Why is s not valid??
+                //Console.WriteLine($"Multipler is a string with the value {s}");
+
+                Console.WriteLine($"Multipler is set {i} {new string('*', i)}");
+            }
+
+            //Illegal as outside the scope of the braces.
+            //Console.WriteLine($"Multipler is set {i}");
+        }
+    }
+}

CSharp7Console/06NullRefTest.cs

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+using System;
+using System.Text;
+
+namespace CSharp7Console
+{
+    public class NullRefTest
+    {
+        public static void NullRefTestExample()
+        {
+            StringBuilder stringBuilder = new StringBuilder();
+            stringBuilder = null;
+
+            Console.WriteLine(stringBuilder.Capacity); // the ide will now say that stringbuilder is null, no need to guess anymore..
+        }
+    }
+}

CSharp7Console/07BinaryLiteralsAndSeparaters.cs

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+using System;
+
+namespace CSharp7Console
+{
+    public class BinaryLiteralsAndSeparaters
+    {
+        public static void BinaryLiteralsExample()
+        {
+            var binary = new[] {0b1, 0b10, 0b11, 0b100, 0b101, 0b110, 0b111, 0x8, 0xF, 32};
+
+            foreach (var binValue in binary)
+            {
+                Console.WriteLine(binValue);
+            }
+
+
+            #region//_ separator
+            var separaters = new int[] { 1_01, 1_02, 1_03, 1_000_000, 1_000_000_000 };
+            foreach (var value in separaters)
+            {
+                Console.WriteLine(value);
+            }
+            #endregion
+        }
+    }
+}